RAWALPINDI, Pakistan -- The most important event in Mohammed Ahsan Dar's life happened six years before he was born. One day in 1953, he says, police patrolling the Indian-controlled part of Kashmir pistol-whipped his father, rendering him "half mad until he found peace in death."

An inbred hatred of India and a fierce Islamic nationalism made a killer of Mr. Dar. First he founded a militant youth group to oppose mostly...